Concentration of barite bearing materials



Patented Oct. 1, 1935 Arthur Crago, Mulberry, Fla., and Harry 0. Motsinger, Pulaski, Tenn., assignors to Phosphate Recovery Corporation, New York, N. Y a corporation of Delaware No Drawing. Application December 12, 1932,

Serial No. 646,872

9 Claims. (Cl. 209-166 This invention relates to the concentration of non-metallic minerals and is herein illustrated as applied to the concentration of barite.-

It has been known that barite and several other so-called non-metallic minerals could be concentrated by flotation to yield a somewhat improved product. Phosphate-bearing minerals have for several years been successfully concentrated on a large scale by flotation methods and with highly satisfactory commercial results, but the same is not true of the other non-metallic minerals.

According to the present invention ground barite can be successfully and commercially concentrated by flotation with the aid of soap-forming acids in the presence of an oil normally free from substantial amounts of free fatty acids, such as fuel oil.

It is found that cleaner concentrates and larger is found that barite can be readily floated away from a gangue of quartz or of calcium carbonate. Crude ground barite ore from Cartersville, Georgia, with a gangue principally of silica, was agitated in water to suspend the clay and other primary slime material present. The suspended fine material was decanted off and sent to waste. In laboratory tests this decanting was repeated 'two or three times. The washed and deslimed product was sieved through a 35-mesh screen and the oversize ground in a laboratory rodmill until it passed a 35-mesh screen. The ground product was added to the undersize and the'mixture again deslimed, usually twice in the laboratory, until substantially all material finer than 200- mesh had beenremovecl.

The finally deslimed material was thickened to contain 71% of solids, and 10% caustic soda solution was added during agitation equivalent to 0.42 pound per ton of solid, then present in the pulp.

After one minute of thorough agitation there was added during continued agitation 1.54 pounds per ton of solids of a 50% solution of free fishoil fatty acids in fueloil, followed by 2.33 pounds per ton of solids of additional fuel oil, and then followed by 0.14'pound per ton of solids of a solution of 75 parts ofcrude rosin residue in 25 parts of kerosene oil as a cheap bubble-forming agent. After two minutes of vigorous agitation the pulp diluted with tap water was agitated in Minerals Separation subaeration' laboratory flotation machine, and a tougher float concentrate was separated for two minutes.

The rougher concentrates were then agitated in the same manner and separated into a cleaner concentrate and a tailing or first middling. The 5 cleaner concentrate thus obtained was reagitated in the same manner to yield a finished concentrate and second middling. In commercial operations these middling products would be returned to the flotation circuit and additional re- 10 covery obtained from them. Inthe following table the results are shown, with the untreated middling separately assayed:

Percent 3 Percent Percent 15 wt. B880 F810: S102.

Crude dry ore 100.

Primary slime- 33. 6 Secondary slime 6. 6 Flotation feed 59. 8 Finished Conc 2i. 1 1st middling 7 2nd middlin 1. 7 Flotation tailing 34. 3

- as oleic acid may be substituted for'the fish-oil 35 fatty acids used in the above examples, and that other oils normally free from substantial amounts of free fatty acid, such as kerosene or cottonseed oil foots, may be substituted for the fuel oil 40 therein.

Having thus described certain embodiments of the invention, what is claimed is:

1. The process which consists in mixing a pulp of ground barite-bearing material relatively free 45 from slimes with alkali, thereafter mixing it with fatty acid and an oil normally free from substantial amounts of free fatty acid, agitating to produce a float concentrate, and separating the float.

2. The process. which consists in grinding 5o barite-bearing material so that a large part of the material is of suitable size, removing the oversize, grinding the oversize, desliming the ground material, mixing a pulp of the ground material with alkali, thereafter mixing it with 55 fatty acid and an oil normally free from substantial amounts of freefatty acid, agitating to produce a float concentrate, and separating the float.

3. The process which consists indesliming ground barite-bearing material, mixing a thick pulp of the ground material with a small fraction of a per cent of strong alkali, thereafter mixing it with fatty acid and an oil normally free from substantial amounts of free fatty acid, agitating the diluted pulp to produce a float concentrate,'and separating the float.

4. The process which consists in grinding barite-bearing material, separating the oversize, grinding the oversize, desliming the resulting ground material, mixing a thick pulp of the ground material with a small fraction of a per cent of strong alkali, thereafter mixing it with fatty acid and an oil normally free from substantial amounts of free fatty acid, diluting the pulp, agitating the diluted pulp to produce a float concentrate, and separating the float.

5. The process which consists in grinding barite-bearing material so that a large part of the material is of suitable size, removing the oversize, grinding the oversize, desliming the ground material, mixing a thick pulp of the ground material with asmall fraction of a percent of caustic soda, thereafter mixing it'with a larger proportion, but less than one percent of fatty acidcarried in fuel oil, adding a fraction of a percent of fuel oil, diluting the pulp after agitation, agitating the diluted pulp to produce a float concentrate, and separating the concentrate.

6. The process which consists in grinding barlte-bearing material so that a large part of the material is of suitable size, removing the oversize, grinding the oversize, desliming the ground material, mixing a thick pulp of the ground material with a small fraction of a percent of caustic soda, thereafter mixing it with a larger proportion, but less than one percent of fatty acid carried in fuel oil, adding a fraction of a per-. cent of fuel oil, diluting the pulp after agitation,

agitating the diluted pulp to produce a float concentrate and cleaning the concentrate by reagltation as a pulp in the substantial absence of further added flotation agents.

'7. The process which consists in grinding 5 barite-bearing material, desliming the ground material, mixing a thick pulp of the ground ma terial with a fraction of its weight of alkali, thereafter agitating the diluted pulp with fatty acid and with oil normally free from substantial amounts of free fatty acid so that a float concentrate is formed substantially dependent upon the presence of the latter oil for the floating of a substantial portion of the float, and separating the float. 8. The process which consists in grinding barite-bearing material, desliming the ground material, mixing a thick pulp of the ground material with a fraction of its weight of alkali, thereafter agitating the diluted pulp with fatty acid and with hydrocarbon oil so that a float concentrate is formed substantially dependent upon the presence of the hydrocarbon oil for the floating of a substantial portion of the float, and

separating the float and cleaning the concentrate by reagitation as a pulp in the substantial absence of further added flotation agents.

9. The process which consists in grinding barite-bearing material so that a large part of the material is of suitable size, removing the oversize, grinding the oversize, desliming the ground material, mixing a thick pulp of the deslimed material with a fraction of its weight of caustic soda, thereafter agitating the diluted pulp with fatty acid and hydrocarbon oil, the fatty acid carried in at least a part of the hydrocarbon oil, so that a float concentrate is formed substantially dependent upon the presence of the hydrocarbon oil for the floating of a substantial portion of the float, and separating the float. 1

ARTHUR CRAGO.

HARRY C. MOTSINGER. 

